General
Peak load (peak demand) is the highest level of electrical power demand observed over a specific time period (such as the highest hourly average in a day or year). Utilities and grid operators plan generation and infrastructure to meet these peak demand periods, which often occur on hot afternoons (due to air conditioning) or early evenings when people return home. Managing peak load is costly because it may require using less efficient “peaking” power plants or demand response programs. Renewable energy and storage can help address peak load: for instance, solar production often aligns with daytime peaks, and batteries can supply power during early evening peaks, reducing the need for peaker plants.